A general in the United States Army, William E. DuPuy (1919-) was known as a combat commander, staff officer, and as a military thinker and one of the spiritual fathers of the revolution in military affairs. Perhaps his most influential assignment, however, was the four-star assignment to the new U.S. Army Training and Doctrine Command (TRADOC) in 1973.He was at the heart of the restructuring of the U.S. Army after the Vietnam War disrupted its tradition, discipline, and ability.
Second World War
He entered the Army as a second lieutenant from the Reserve Officers Training Corps in 1941, landed in the Battle of Normandy, and, by the end of the Second World War, was a 25-year-old battalion commander.
During the Korean War, he served as a battalion and regimental commander during the Cold War. While a battalion commander, he served under Hamilton H. Howze, whose tactical combat pulled together, in an American context, things he had seen as effectively used by Second World War German troops. He particularly appreciated their sense for the use of terrain, and their use of responsive direct fire rather than waiting for air and artillery support.
His responsibilities grew during the Vietnam War, where he first served as operations officer for the Military Assistance Command, Vietnam]. During that time, he decided that as long as the enemy could fight from the sanctuaries of Cambodia, Laos, and North Vietnam, it was impossible to bring adequate destruction on the enemy, and the model was inherently flawed.
In the Vietnam experience, he became concerned that the extreme U.S. firepower superiority had formed bad habits. The man who had studied terrain use by the Germans, and the overwatch methods of Gen. Howze, concluded that a genera tion of helicopter-borne commanders lost their respect for the ability of terrain to hamper the mobility of units on the ground. They became so dependent on close air support and artillery that they ignored basic infantry defense. "None of those," DePuy said in 1974 when referring to Vietnamese-style U.S. defensive positions, "would survive for two seconds on the modern battlefield."
Subsequently, he commanded the 1st Infantry Division in Vietnam. Returning to Washington, he became the Service as the Special Assistant for Counterinsurgency and Special Activities (to the Chairman of the Joint Chiefs of Staff and as assistant vice chief of staff of the Army in Washington, D.C.
In the latter position, he headed the interim Continental Army Command (CONARC), which was responsible for both doctrine and preparation. The mobilization mission went to the new Forces Command, and he went to TRADOC.
Pre-TRADOC, the Army had general principles, but no formal doctrine: the statement of "how we fight" above the tactical level. Developed under Dupuy was the first version, published in 1976, of Field Manual 100-5, Operations, which established Army doctrine for operational art. The first edition featured a Cold War model called "Active Defense", but the tradition of doctrinal thinking emerged. It introduced the AirLand Battle doctrine but did not tightly integrate it with other doctrine. Nevertheless, FM100-5 was the first of a series, under various names and numbers, of Army "capstone" documents. Joint U.S. doctrine arguably involved from that Army development, along with the more informal "maneuvrist" thinking from COL John Boyd of the Air Force and GEN Alfred M. Gray, Jr.Cite error: Invalid
invalid names, e.g. too many of the Marines. The idea of doctrine has been one of the drivers of the restructuring of the United States Army.
We are not in this business to be good guys. . . . Nice, warm human relationships are satisfying and fun, but they are not the purpose of an Army. Establishing the most marvelous, warm, sympathetic and informed relationships is unimportant, except in the context of making the team work better. 
- Gen. William E Dupuy, August 1, 1988 interview, quoted by McNamara, In Retrospect, pages 212 and 371.
- Herbert, Paul H. (1988), Deciding what has to be done General William E. DePuy and the 1976 Edition of FM 100-5, Operations, Combat Studies Institute, United States Army Command and General Staff College, Leavenworth Papers No. 16